The Kittila mine is located in the Lapland region of northern Finland, approximately 900 km north of Helsinki and 150 km north of the Arctic Circle. With a mine life estimated through 2034, Kittila is our longest-life mine; its proven and probable mineral reserves contain 4.1 million ounces of gold (29 million tonnes grading 4.40 g/t gold) as of December 31, 2019.
The Kittila property covers 199 square km, stretching 25 km along the Suurikuusikko Trend, a major gold-bearing shear zone. The mine area includes a group of six gold deposits along a 4.5-km segment of the trend. The largest of the deposits are the Suuri, Roura and Rimpi zones that contain most of the current mineral reserves and mineral resources at Kittila. The other deposits are the Etela and Ketola zones and the Sisar Zone. The Company has approved a 160- to 170-million-euro expansion project that will include the construction of a 1,044-metre deep shaft, a processing plant expansion that is expected to increase throughput by 25% to 2.0 million tonnes per year, as well as other infrastructure and service upgrades. The expansion project is expected to increase the efficiency of the mine and decrease or maintain current operating costs while providing access to the deeper mining horizons. This increased mining rate will be supported by the development of the Rimpi and Sisar zones.
Geology
The region around the Kittila mine is underlain by mafic volcanic and sedimentary rocks of the Kittila Greenstone Belt that trend north to north-northeast and are nearly vertical. This greenstone belt is similar to those hosting our Canadian deposits in Quebec’s Abitibi region and Nunavut. The contact between iron-rich and magnesium-rich volcanic and sedimentary rocks consists of a transitional zone (the “Porkonen Formation”) varying between 50 and 200 m in thickness. This zone is strongly sheared, brecciated and characterized by intense hydrothermal alteration and gold mineralization, features consistent with major brittle ductile deformation zones. The zone is part of a major north-northeast-oriented shear zone (the “Suurikuusikko Trend”). The Porkonen Formation hosts the Kittila gold deposit, which contains multiple mineralized zones stretching over a strike length of more than 25 km.
Mineralization
Work has focused on a 4.5-km segment of the Suurikuusikko Trend that hosts the six main zones of known gold mineral reserves and mineral resources – Ketola, Etela, Suuri, Roura, Rimpi and Sisar. The Sisar Zone is located to the east of the main Kittila ore zone, and in close proximity to existing underground infrastructure. Gold mineralization in these zones is associated with intense hydrothermal alteration (carbonate-albite-sulphide), and is almost exclusively refractory, locked inside the fine-grained sulphide minerals arsenopyrite and pyrite. The remainder is free gold, which is manifested as extremely small grains of gold in pyrite.
Mining
The underground method is open stoping followed by delayed backfill. Approximately 16 km of tunnels are developed each year to ensure sufficient ore production is available to keep the mill supplied. After extraction, stopes are filled with cemented backfill or paste backfill to allow the safe mining of adjacent stopes. Ore is trucked to the surface crusher using underground haul trucks via the 4,400-metre-long ramp access system. An expansion project includes the construction of a 1,044-metre-deep shaft that will have hoisting capacity of 2.7 million tonnes per year (2.0 million tonnes of ore and 0.7 million tonnes of waste). In addition, the shaft is expected to provide access to the mineral resource areas below 1,150 m, where recent exploration programs have shown promising results.
Processing
Approximately 5,000 tonnes of ore/day are fed to the processing plant. The ore is treated by grinding, flotation, pressure oxidation, and carbon-in-leach circuits. Kittila has Agnico Eagle’s only pressure oxidation circuit (autoclave), which is required because of the ore’s refractory nature. Gold from the leach circuit is recovered from the carbon in a Zadra elution circuit and recovered from solution using electrowinning, and then smelted in an electric induction furnace and poured into doré bars. Gold recovery of 86% is expected over the life of the mine. A four-phase mill expansion is expected to increase throughput from the current level of 1.6 million tonnes per year to 2.0 million tonnes per year by 2021. The mill expansion will involve installation of a secondary crushing circuit, new thickener and reactor capacity, and minor modifications to the existing grinding circuit and autoclave.
Exploration
Exploration at the Kittila mine is focused on extending the Main and Sisar zones northward, southward and at depth in the Roura and Rimpi areas to increase the mineral reserves in the large orebody. Sisar is subparallel to and 50 to 300 m east of the main Kittila mineralization.
The main exploration ramp to the north is being used to test the extensions of the Roura and Rimpi Zones. Two internal ramps are being driven off the main exploration ramp for converting and exploring Sisar Top Zone and Rimpi Deep mineral resources between 800 and 1,400 m below surface.
In 2020, the Company expects to carry out drilling focused on the Main Zone in the Roura and Rimpi areas as well as the Sisar Zone. The goal is to further explore the Kittila mineral reserve and mineral resource potential and demonstrate the economic potential of the Sisar Zone as a new mining horizon at Kittila.
Development Project
Sisar Zone
In 2015, a new sub-parallel zone of mineralization – known as the Sisar Zone – was discovered by exploration drilling from the underground ramp being driven northward.
The Sisar Zone is located to the east of the main Kittila ore zone, approximately 50 to 300 m east of existing underground infrastructure. Initial mineral reserves were estimated at the Sisar Zone at year-end 2016 (as part of the total Kittila reserves estimate). Drilling is ongoing to further evaluate the Sisar Zone, which forms a roughly triangular shape located between approximately 775 and 1,910 m below surface along a 1,900-metre north-south strike length; the zone remains open at depth and along strike.